Door latches



P. S. JEAVONS DecJO, 1968 DOOR LAI'CHES 2 Sheets-Sheet 1 Filed April 24, 1967 INVEN R l ll/LIP Sum/4210000 Jr a:

wry 7% ATTORNEYS Dec. 10, 1968 P. s. JEAVONS 3,

' noon LATCHES Filed April 24, 1967 2 Sheets-Sheet 2 IF I FIG. 6- F/s. Z

I N V E N TO R PHIL IP Swwsswoaa la-Aways ATTORNEYS United States Patent Oflice 3,415,559 Patented Dec. 10, 1968 3,415,559 DOOR LATCHES Philip Swingewood Jeavons, Birmingham, England, assignor to Wilniot-Breeden Limited, Birmingham, England Filed Apr. 24, 1967, Ser. No. 633,194 Claims priority, application Great Britain, July 15, 1966, 31,795/ 66 21 Claims. (Cl. 292-216) ABSTRACT OF THE DISCLOSURE The application relates to a door latch for a motor vehicle and comprising a recessed body and a latch member in the form of a rotatable circular disc received in the body recess. The boundary of the recess locates and provides a bearing for the latch member which is peripherally notched for latching engagement with a striker. A detent engages the latch member and acts to retain the latter in the latching position.

This invention relates to door latches and is of particularly advantageous, though by no means exclusive, application to door latches for motor vehicles.

According to the invention a door latch has a recessed body and a latch member in the form of a rotatable circular disc received in the body recess with the boundary of the recess locating and providing a bearing for the latch member which is peripherally notched for latching engagement with a striker and formed for engagement by detent means which act to retain the latch member in the latching position.

The latch member may be in the form of a simple disc the outer diameter of which takes a bearing in the body recess, although the disc periphery may be stepped with a step of reduced diameter bearing against the recess boundary.

Preferably the body is in the form of a main block on and in which the detent means and other latch control and operating elements are mounted, and which is conveniently moulded from a synthetic plastic material with a circular recess for the latch member. An outer steel cover plate attached to the block may partially overlap and serve to retain the latch member in the recess. A backplate is preferably provided to which the body block is fixed and On which control and operating elements are mounted, and when the latch is fitted to a door panel the latter may be sandwiched between the block and the backplate which are connected together, and with the cover plate, by the fixing screws.

The block preferably has a groove providing clearance for entry of the striker for initial engagement and subsequent latching with the latch member, and although the striker can be in the form of a pin the latch is conveniently designed for use with a striker in the form of a generally U-shaped loop the side limbs of which are attached to the door frame With one of these limbs arranged for engagement with the latch member. The latch member is preferably lightly spring loaded towards the unlatched position, in which it is thus retained when the door is open and in which the striker engaging notch is correctly presented for engagement by the striker on subsequent door closure.

The detent means conveniently take the form of a hooklike detent lever which engages peripheral notches on the latch member formed to act in the manner of ratchet teeth, two such notches preferably being provided for retention of the latch member in safety-latching and fullylatching positions respectively. The detent lever may be mounted in the block and connected through an operating link to a contactor lever pivotally mounted on the backplate and movable to effect latch release; the contactor lever may be directly engageable by an external door pushbutton for release of the latch from outside the door, and it may be engaged by a remote control lever also pivotally mounted on the backplate and connectable to an internal release linkage for release of the latch from inside the door.

Aspring for the detent lever, which engages that lever with the notched latch member periphery, may also perform the function of providing said light spring loading of the latch member towards the unlatched position.

Preferably the body has a slot aligned with the fastening direction and along which the striker travels to the latched position. With the latch member in the fullylatching position the latch engaging notch thereof may cross the slot so that any tendency for the striker to be Withdrawn wedges the latter between one side of the slot and the opposite side of the notch. The normal door seal pressure will provide such a wedging action and hence with a motor vehicle application supply the necessary vertical restraint to prevent door rattle. In the safetylatching position the notch is preferably disposed substantially laterally of the slot so that there is no wedging action.

The slot should desirably be disposed as small a distance below the centre of the latch member as is practicable, so that the seal pressure and any tendency for the door to open imposes the minimum turning moment on the latch member. The present invention has the advantage that the absence of a shaft or spindle for the latch member enables the slot to be taken very close to the rotational centre, with very small turning moments on the latch member having to be withstood and consequent low loading of the detent lever.

Wedging providing vertical restraint may additionally, or alternatively, be obtained by means of a spring-loaded wedge member mounted at one side of the body so as to engage the striker when the latter is in the latched position. A further alternative arrangement may comprise a flap or vane, or separate plate, housed in or part of the latch body and suitably cushioned by resilient material such as rubber.

The invention will now be further described with reference to the accompanying drawings which illustrate, by way of example, a motor vehicle door latch in accordance with the invention. In the drawings:

FIGURE 1 is an external face view of the latch in the latching condition,

FIGURE 2 is a similar view with an outer cover plate removed, but in the unlatched condition,

FIGURE 3 is an internal view opposite to that of FIGURE 1,

FIGURE 4 is a side view in the direction of the arrow IV in FIGURE 3,

FIGURE 5 is a sectional view on the line V-V in FIGURE 2 showing the latch as fitted toa vehicle door, but with some of the internal operating elements omitted, and

FIGURES 6 and 7 are respectively face and side views of a suitable striker for use with the latch illustrated.

The latch has three main structural components; a recessed body 1 provided by a block moulded from a synthetic plastic material and formed for fitting externally to an edge panel 2 of the door as shown in FIGURE 5, a backplate 3 for fitting internally of the panel 2, and the outer cover plate 4. As shown in FIGURE 5, when the latch is fitted the panel 2 is sandwiched between the block 1 and the backplate 3; four fixing screws 5, the heads of which are countersunk in the plate 4, are threaded into plunged bores in the plate 3 and serve to hold the cornplete assembly together and firmly attached to the door. The block 1 is moulded with a peripheral rim 6 within which the plate 4 is recessed.

On its outer face the block 1 also has two moulded-in recesses, namely a lower circular recess 7 above which is disposed a generally horizontal recess 8 of elongated form. As viewed externally in the fitted position, i.e. as shown in FIGURES 1 and 2, the recess 8 breaks into the recess 7 between the ten oclock and eleven oclock positions so that the recesses communicate at the trailing side of the block 1, considering movement during a latching operation.

A latch member 9 in the form of a peripherally notched circular disc is rotatably mounted in the recess 7, the side wall of that recess providing a bearing for the latch member 9 which is pivotless. Thus the member 9 turns about its centre 10 and is axially located on the one hand by the base of the recess 7 and on the other hand by the cover plate 4. The steel cover plate has a pressed-in portion 12 which engages the latch member 9 in the region of the centre 10 in order to retain the latch member in the recess 7. The cover plate 4 not only retains the latch member 9 but also provides a shroud for the latter.

The latch member 9 is notched at 13 for latching engagement with the striker which, as shown in FIGURES 6 and 7, is conveniently in the form of a generally U-shaped loop 14 of steel rod with side limbs 15 which have cranked ends welded to a pressed steel mounting plate 16 for at tachment to the vehicle body. The mounting plate is generally saddle shaped with the limbs 15 passing through apertures in the plate so that the cranked ends can be welded to the rear of the plate 16.

When the striker is mounted the intermediate limb 17 thereof is aligned with the fastening direction, i.e. is generally horizontal as shown in FIGURES 6 and 7, and during a latching operation horizontal sections of the side limbs 15 in front of the plate 16 and the limb 17 enter and travel along a slot 18 in the body 1. The slot 18 extends behind the latch member 9 and crosses the latching notch 13; it has a closed trailing end and, as shown in FIGURES 1 and 2, has a flared mouth opening at the leading edge of the block 1. .The cover plate 4 is similarly slotted at 19 to provide clearance for the striker loop 14.

In the unlatched position of the latch member 9, towards which it is lightly spring loaded by a spring 20' one limb of which engages a peg which projects from the inner face of the member 9, the latching notch 13 is as shown in FIGURE 2 disposed with its mouth in register with the slot 18. During door closure the leading striker limb 15 can thus enter the notch 13 to engage the latch member 9 and apply to that member a turning moment which overcomes the light spring loading. The latch member is thus turned to the latching position in which the notch 13, as shown in FIGURE 1, crosses the slot 18 below which the mouth of the notch 13 is now disposed.

The periphery of the latch member 9 has two further spaced notches 22 and 23 which provide a ratchet-toothed formation for engagement by a detent lever 24 acting as a pawl and pivotable in the recess 8 on a pivot 25. As shown in FIGURE 5, the pivot 25 is supported rearwardly of the latch member 9 in the body moulding 1 from which it projects for engagement with a locating bore in the panel 2. Forwardly of the latch member 9 the outer end of the pivot 25 is supported in a bore 21 in the cover plate 4.

The spring 20 which acts on the latch member 9 is in the form of a torsion spring which surrounds the pivot 25 and also acts on the lever 24, thereby urging a hook shaped trailing end 26 of that lever into engagement with the periphery of the latch member 9 through the gap between the recesses 7 and 8. During door closure and resultant turning of the latch member 9 to the latching position, the notch 22 is initially engaged by the lever 24 to provide a safety-latched condition; when the door is fully closed the notch 23 is engaged by the lever 24 to retain the latch member 9 in the fully-latched condition. Thus the detent lever 24 resists any tendency for the striker loop 14 to be withdrawn from the block 1 and secure latching is obtained.

The described loop formation of the striker, with the intermediate limb 17 passing behind the latch member 9, provides excellent anti-burst characteristics. Thus during a vehicle collision forces tending to separate the striker and latch member both longitudinally and laterally of the vehicle are resisted, so that the door does not burst open.

The latching notch 13 has an outer and generally radially disposed portion 13a inwardly of which the notch curves to a radiused end portion 13b disposed close to the centre 10. Thus in the latching position the inner end 13b is disposed close to and almost directly below the centre 10. The slot 18 is also disposed as close below the centre 10 as is practicable so that any tendency for the door to open imposes the minimum turning moment on the latch member 9, the limiting condition being that the construction must be such that a suflicient moment arm is present to turn the latch member 9 without applying an undue force to the door during latching and unlatching operations. The low turning moment on the latch member 9 provides correspondingly low loading of the pawl lever 24.

As a result of the curved form of the notch 13, which towards its inner end curves more closely into alignment with the slot 18 although it always crosses the latter, any tendency for the door to open provides a wedging action in which the leading limb 15 of the striker is wedged between the upper side of the slot 18 and the opposite lower side of the latching notch 13. Suflicient Wed-ging may be obtained as a result of the normal door seal pressure to provide adequate vertical restraint and prevent door rattle, although if desired additional vertical restraint may be provided by means of a spring-loaded wedge or the like engaging the striker loop 14. As shown in FIGURE 2, the latching notch 13 has a slightly flared mouth to assist latching engagement and is of inwardly decreasing width although adequate side clearance for the striker limb 15 is provided along the eflective length of the notch.

Internal operating elements mounted on the backplate 3 are operative for both external and internal release of the latch and also for locking thereof. A contractor lever 27 pivotally mounted on the backplate 3 has an arm 28 connected to one end of an operating link 29 bent to a cranked form from steel rod with a central portion parallel to the backplate and an upper end portion which projects through an arcuate slot 30 in the backplate 3. The panel 2 and block 1 are similarly slotted to provide clearance for the link 29 the upper end of which engages a hole 31 in the detent lever 24 adjacent the trailing end thereof. The lower cranked end of the link 29 passes through the lever arm 28 at 32 and provides one anchorage for a contactor return spring 33, the other end of which is anchored to the backplate 3 at 34.

External release of the latch, i.e. release from outside the door, is achieved by means of a pushbutton (not shown) mounted on an outer door panel in a position such that the pushbuton shaft directly engages the flanged edge of an upwardly directed arm 35 of the lever 27. This turns the lever 27 in an anti-clockwise direction, as viewed in FIGURE 3, to lift the link 29 and with it the leading end of the detent lever 24 which is thus moved clear of the notch 23 in the latch member 9. The striker loop 14 can now be withdrawn with attendant movement of the latch member 9 to the unlatched position in which it is retained by the spring 20.

Internal release of the latch is achieved by means of a bellcrank remote control lever 36 which is pivotally mounted on a bent-up flang portion 37 of the backplate 3. The lever 36, which for clarity is omitted from FIG- URE 3, has an upwardly directed arm 38 for connection to a remote control linkage (not shown) operative movement of which turns the lever 36 in a clockwise direction as viewed in FIGURE 4. During such movement a generally horizontal arm 39 of the lever 36 engages above a third arm 40 of the contactor lever 27, thereby producing releasing movement of the latter lever.

Locking is achieved by means of a cranked locking pin 42 one end of which is slidable in a bore 43 and movement of which is controlled by a locking lever 44 mounted on the flange 37 between that flange and an attached bridge plate 45. The lever 44 has a boss 46 which projects through the flange 37 and has a non-circular bore 47 for coupling to a locking shaft (not shown) of a key-operated locking mechanism mounted on the outer door panel.

As can be seen from FIGURE 2, the pin 42 projects into the body recess 8 immediately below the leading end of the detent lever 24. In the locking position it is dis posed beneath the lever 24 and hence blocks releasing movement of that lever 24 which cannot be freed from the latch member 9 to release the latter. As shown in FIGURE 2, with the latch member 9 in the unlatched position the detent lever 24 is disposed partially in front of the bore 43. This blocks any attempt to move the locking pin 42 to the locking position, and hence the latch cannot be locked with the door open. This avoids the danger of persons accidentally locking themselves out of the vehicle, or effecting locking with the door open to produce a solid slam condition which would prevent door closure.

The locking lever 44 is indexed so that it is reliably retained by means of an overcentre spring in either the locking or th unlocking position; it can be connected to a suitable internal door locking member, for example a sill control member which projects from the door sill in the usual manner.

I claim:

1. A door latch having a recessed body and a latch member in the form of a rotatable circular disc received in the body recess with the boundary of the recess locating and providing a bearing for the latch member which is peripherally notched for latching engagement with a striker and formed for engagement by detent means which act to retain the latch member in the latching position.

2. A door latch according to claim 1, wherein the latch member is in the form of a simple disc the outer diameter of which takes a bearing in the body recess.

3. A door latch according to claim 1, wherein the body is in the form of a main block in which the detent means are mounted.

4. A door latch according to claim 3, wherein the body moulded from a synthetic plastic material with a circular recess for the latch member and a communicating recess in which the detent means are mounted.

5. A door latch according to claim 1, wherein the detent means take the form of a hook-like detent lever which engages peripheral notches on the latch member formed to act in the manner of ratchet teeth.

6. A door latch according to claim 5, wherein two detent notches are provided for retention of the latch member in safety-latching and fully-latching positions respectively.

7. A door latch according to claim 3, wherein an outer steel cover plate attached to the block partially overlaps and serves to retain the latch member in the corresponding body recess.

8. A door latch according to claim 20, arranged for mounting on a door panel with the panel sandwiched between the backplate and the recessed body.

9. A door latch according to claim 8, wherein an outer cover plate attached to the block partially overlaps and serves to retain the latch member in the block, and the backplate is threaded for the reception of fixing screws which pass through the cover plate, the block and the door panel.

10. A door latch according to claim 20, wherein the detent means comprise a lever mounted in the block for engagement with the latch member and connected through an operating link, which passes through the backplate, to a contactor lever of said control and operating elements which is pivotally mounted on the backplate and movable to effect latch release.

11. A door latch according to claim 10, wherein the contactor lever is arranged for direct engagement by an external pushbutton for release of the latch fromoutside the door.

12. A door latch according to claim 10, wherein said control and operating elements include a remote control lever which is also pivotably mounted on the backplate and engages the contactor lever to produce releasing movement thereof, the remote control lever being arranged for connection to an internal release linkage for release of the latch from inside the .door.

13. A door latch according to claim 1, wherein an operating spring of the detent means also acts to provide light spring loading of the latch member towards the unlatched position.

14. A door latch according to claim 20, wherein the body cut away provides a slot aligned with the fastening direction and along which the striker travels during a latching operation.

15. A door latch according to claim 14, wherein the body slot acts to guide the striker to the latched position.

16. A door latch according to claim 14, wherein with the latch member in the fully-latching position the latch engaging notch thereof crosses the slot and the notch formation is such that any tendency for the striker to be withdrawn wedges the latter between one side of the slot and the opposite side of the notch.

17. A door latch according to claim 1, wherein an outer cover plate partially overlaps the body to retain the latch member in the recess and has a slot for entry of the striker and straddles a portion of the latch member when the latter is in the latching position, which portion is sandwiched between the cover plate and the striker to provide anti-burst strength axially of the latch member.

18. A door latch according to claim 1, wherein the striker engages the latch member close to the rotational axis thereof, whereby to decrease the load on the detent means and hence provide high anti-burst strength in the fastening direction.

19. A door latch comprising a body formed with a recess, a rotatable latch member of generally circular disc-like form with an outer peripheral surface at least part of which forms a bearing surface which engages the boundary of the recess, the periphery of the latch member having a first notch for latching engagement with a striker and a second notch, and detent means which act to retain the latch member in the latching position for which purpose the detent means engage said second notch in the latch member.

20. A door latch comprising a backplate, a main body block fixed to the backplate and formed with a recess, a latch member in the form of a rotatable circular disc received in the body recess with the boundary of the recess radially locating and providing a bearing for the latch member, the latch member being peripherally notched for engagement with a separate striker and the body block cut away to allow entry of the striker during a latching operation, detent means which act to retain the latch member in the latching position, the latch member being engaged by the detent means, and latch control and operating elements mounted on the backplate.

21. A door latch and striker combination, the latch comprising a body with a recess, a latch member in the form of a rotatable circular disc mounted in the recess with a peripheral surface which takes a bearing against the boundary of the recess for radial location of the latch member, and detent means which engage the latch member to retain that member in the latching position, and the striker being in the form of a generally U-shaped loop attachable to the door frame and with one of the side 7 limbs of the loop arranged for latching engagement with 2,865,668 a peripheral notch in the latch member. 2,996,327 3,049,371 References Cited 3,131,959 5 3,232,656

UNITED STATES PATENTS Krause 292-2l6 France et a1. 292-216 X Daly 292-128 Werner 292--341.17 Coverley et al 292-280 RICHARD E. MOORE, Primary Examiner. 

